The present invention relates to image forming apparatuses that form images on sheet shaped image recording media.
Toners, inks, and heat transfer ribbons are available as the coloring materials for forming images on sheet shaped image recording media, and there are image forming apparatuses having various types of structures for forming images on sheets using these coloring materials. For example, regarding toners which are one type of coloring materials, there are various types of toners that differ from each other in their characteristics such as diameter or shape of particle, and image forming apparatuses have been proposed from the past that can form images on sheets even if different types of toners with different characteristics are used.
The technology disclosed in Patent Document 1 carries out image formation even when a genuine toner cartridge used and also when a non-genuine toner cartridge is used by changing the operating mode thereby preventing deterioration in image quality due to differences in the characteristics of the toner.
Further, the technology disclosed in Patent Document 2 is one in which a plurality of process cartridges are prepared that have toners of different characteristics such as particle diameter or toner manufacturing method, and the process cartridge that is installed in the image forming apparatus is made different depending on the purpose such as image quality, etc.
However, in the conventional technology, there is no image forming apparatus in which coloring materials of the same color but differing characteristics can be loaded at the same time, and when forming images using coloring materials with different characteristics is desired, it was cumbersome because it was necessary to replace with the cartridge containing the coloring material to be used. In other words, it was not possible to carry out image formation easily according to the user requirements related to the desired image quality or the cost of the coloring material, etc.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2005-326739    Patent Document 2: Japanese Unexamined Patent Application Publication No. 2000-172132